Scheduling sessions of multi-speaker events

ABSTRACT

A method of scheduling events includes receiving event data specifying sessions for an event, an event duration that encompasses a plurality of time slots, a respective duration for each session, a respective start time for the event and the sessions, and information describing a plurality of attendees; generating a first list of each possible set of time slots within which each session can be scheduled based upon the respective start times; generating a second list by removing each possible set of time slots for each session that is less than the duration specified for the session; performing a scheduling process for each session; and sending a respective electronic message presenting the schedule to each attendee.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of, and claims priority to, U.S.application Ser. No. 12/254,135 filed on Oct. 20, 2008, claims thebenefit of European Patent Application No. 08305650.7, filed Oct. 7,2008 at the European Patent Office, the disclosure of which is herebyincorporated by reference herein in its entirety.

BACKGROUND

Exemplary embodiments of the present invention relate electronic eventsmanagement, and more particularly, to scheduling sessions of an eventwith multiple attendees based on a set of constraints.

The use of calendaring and scheduling technology has grown considerablyin the last decade. Nevertheless, meeting scheduling can present aninherently difficult and time-consuming task that requires multipleparties to interact and consult their various calendars to reach anagreement on a mutually acceptable time. The scheduling task becomesmore difficult when the meeting is an event such as a conference or anoffice visit that involves a number of different participants that willbe attending a number of sessions or sub-meetings related to differentsub-topics, in which attendance is required for certain participants atcertain sessions or sub-meetings. Where the scheduling task involves anevent that includes multiple sessions or sub-meetings each beingorganized by separate people and/or encompassing further sub-sessions orsub-meetings, the process becomes even more complex. The schedulingprocess for an event must take into account numerous constraints thatare set by the participants, and as a result, scheduling a meeting or anevent can be a lengthy and time consuming process that involvescontacting the attendees, soliciting open times from the attendees,identifying free time slots that are acceptable to the attendees, andthen notifying the attendees once an appropriate time is found. Theoverhead involved with scheduling a meeting or an event increases withthe number of attendees and other resources that must be coordinated forthe event to occur.

Automated software services and tools designed to assist the schedulingprocess have been developed to attempt to reduce the overhead ofscheduling a meeting or an event. Typically, such a service will includea server shared by an organization that provides a common database forstoring information related to a calendar of events (for example,meetings, conferences, and other appointments) each member of theorganization is scheduled to attend. People wishing to organize meetingscan use this shared information to determine whether an appropriatemeeting time is available. For example, a scheduling service may allow auser who is organizing a conference (the “chair”) to specify a list ofmandatory attendees and a list of optional attendees from theorganization for a meeting. The scheduling service then determines oneor more proposed times that all the mandatory attendees can attend ameeting based on data in the shared electronic calendar stored in thecommon database for the organization. The proposed times are presentedone at a time in chronological order. The scheduling service may alsolist the optional attendees who are also available to attend eachproposed time. The organizer can then select one of the proposed timesfor the meeting and send a message to each of the attendees invitingthem to attend the meeting.

While greatly simplifying the task of finding times when a limitednumber of persons are available for a conference, existing schedulingservices still have drawbacks. For instance, the process of selecting anappropriate meeting time is manual and time consuming. The organizer mayhave to scan through numerous calendars and across large date ranges tofind an appropriate time. Additionally, there are privacy implicationsthat are at odds with publishing private data that involves thewhereabouts of an individual in the shared calendar in such an approach.

SUMMARY

An exemplary embodiment of a method of scheduling events having multiplemeetings and multiple attendees includes receiving a set of event dataspecifying a set of sub-meetings for an event including one or moresessions for the event, an event duration that encompasses a pluralityof time slots, a respective duration for each sub-meeting, a respectivestart time for the event and each of zero or more of the sub-meetings,and a set of information describing a plurality of event attendees thatincludes a respective list of zero or more mandatory attendees for eachsub-meeting; generating a first list of each possible set of time slotsfrom the plurality of time slots for each session within which thesession can be scheduled based upon the specified lists of zero or moremandatory attendees and the respective start times for the sub-meetings;generating a second list by removing each possible set of time slotsfrom the first list for each session that is less than the durationspecified for the session; individually performing a scheduling processfor each session that comprises allocating a respective set of timeslots for the session in an event schedule, removing each possible setof time slots for the session that is not equivalent to the set of timeslots allocated for the session from the second list, and removing eachpossible set of time slots for each other session that includes at leastone time slot allocated for the session in the event schedule from thesecond list; and sending a respective electronic message presenting theevent schedule to each event attendee of the plurality of eventattendees.

The shortcomings of the prior art can also be overcome and additionaladvantages can also be provided through exemplary embodiments of thepresent invention that are related to computer program products and dataprocessing systems corresponding to the above-summarized method are alsodescribed and claimed herein.

Additional features and advantages are realized through the techniquesof the present invention. Other embodiments and aspects of the inventionare described in detail herein and are considered a part of the claimedinvention. For a better understanding of the invention with advantagesand features, refer to the description and to the drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The subject matter that is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other objects, features, andadvantages of the invention are apparent from the following detaileddescription of exemplary embodiments of the present invention taken inconjunction with the accompanying drawings in which:

FIG. 1 is a block diagram illustrating an exemplary event organizingsystem within which exemplary embodiments of the present invention canbe incorporated.

FIG. 2 is a block diagram illustrating an exemplary embodiment of anevent management mechanism in accordance with the present invention.

FIGS. 3 a and 3 b respectively illustrate hierarchical tree and tablerepresentations of an example set of event data.

FIGS. 3 c and 3 d illustrate example table representations for possiblescheduling data that may be generated by exemplary embodiments of thepresent invention.

FIGS. 4 a and 4 b are flow diagrams illustrating an exemplary embodimentof an event scheduling process in accordance with the present invention.

FIG. 5 is a block diagram illustrating an exemplary computer systemwithin which exemplary embodiments of the present invention can beimplemented.

The detailed description explains exemplary embodiments of the presentinvention, together with advantages and features, by way of example withreference to the drawings. The flow diagrams depicted herein are justexamples. There may be many variations to these diagrams or the steps(or operations) described therein without departing from the spirit ofthe invention. For instance, the steps may be performed in a differingorder, or steps may be added, deleted, or modified. All of thesevariations are considered a part of the claimed invention.

DETAILED DESCRIPTION

While the specification concludes with claims defining the features ofthe invention that are regarded as novel, it is believed that theinvention will be better understood from a consideration of thedescription of exemplary embodiments in conjunction with the drawings.It is of course to be understood that the embodiments described hereinare merely exemplary of the invention, which can be embodied in variousforms. Therefore, specific structural and functional details disclosedin relation to the exemplary embodiments described herein are not to beinterpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the presentinvention in virtually any appropriate form. Further, the terms andphrases used herein are not intended to be limiting but rather toprovide an understandable description of the invention.

Exemplary embodiments of the present invention described herein can beimplemented to provide a mechanism for event management that allows auser to organize and schedule an event, such as a conference withmultiple presentations or an office visit, that involves a number ofdifferent participants that will be attending a number of sessions ormeetings related to different sub-topics, in which attendance is eitheroptional or mandatory for certain of the participants at certain of themeetings, and in which the multiple meetings can each further encompasssub-sessions for which attendance may be either optional or mandatoryfor certain participants of the meeting. Exemplary embodiments can befurther implemented to permit the event-organizing user (that is, “thechair” for the event) to assign a chair for each of the meetings andsub-sessions of the event. In these embodiments, once the event chairhas established the initial set of meetings for the event, the assignedchair for each meeting can then utilize the mechanism for eventmanagement to organize and schedule the sub-meetings for the meeting towhich the chair has been assigned.

Referring now to FIG. 1, an electronic event organizing system 100within which exemplary embodiments of the present invention can beincorporated is illustrated. As will be described, electronic eventorganizing system 100 can be utilized for scheduling an event in which anumber of different participants will each be attending a number ofdifferent sessions or meetings. System 100 includes a network 110,client computers 120 c, 120 b, 120 c (collectively referencedhereinafter as hosts 120), a calendar database system 130, an eventdatabase system 160, and an event management server 190.

According to the client-server model of computer process interactionutilized in the present exemplary embodiment, a client process sends amessage including a request to a server process, and the server processresponds by providing a service. The server process may also return amessage with a response to the client process. Often the client processand server process execute on different computer devices, called hosts,and communicate via a network using one or more protocols for networkcommunications. As used herein, the term “server” refers to the processthat provides the service, or the host computer device on which theprocess operates. Similarly, as used herein, the term “client” refers tothe process that makes the request, or the host computer device on whichthe process operates. In addition, a process executing as a server canbe broken up to run as multiple servers on multiple hosts (sometimescalled tiers) for reasons that include reliability, scalability, andredundancy, but not limited to those reasons.

In the present exemplary embodiment, network 100 can be any network thatconnects a variety of users of client computers, including, but notlimited to, local area networks (LANs), wireless networks, wide-areanetworks (WAN), the Internet (a network of heterogeneous networks usingthe Internet Protocol, IP), and virtual private networks. In exemplaryembodiments in which electronic event organizing system 100 is a single,stand-alone system, network 110 may be omitted.

Clients 120 are computer devices to which a population of potentialparticipants in events (the “conference population”), or their humanagents (for example) secretaries and assistants, have access. Clients120 are connected to network 110. For the purposes of illustration,three clients 120 a, 120 b, 120 c are shown in FIG. 1. In otherexemplary embodiments, more or fewer clients are connected to network110. In exemplary embodiments in which electronic event organizingsystem 100 is a single, stand-alone system, only one client is used.Clients 110 can include any device capable of accessing or providingevent scheduling information, such as desktop personal computers (PCs),laptops, hand-held personal digital assistants (PDAs), wireless phones,and other devices.

In the present exemplary embodiment, electronic event organizing system100 includes a calendar database system 130. Calendar database system130 includes a calendar database server 140 and user calendar data 150on one or more storage devices. Calendar database server 140 controlsthe storage and retrieval of user calendar data 150. Calendar databaseserver 140 provides services to allow individual users, who may bepersons operating one of clients 120, to maintain individual electroniccalendars on system 100. The information regarding each individualelectronic calendar is maintained in user calendar data 150. Morespecifically, user calendar data 150 generally includes one or more datastructures that hold data indicating a person from the population andzero or more appointments for that person, including data indicating astart date and time and stop date and time for the appointment. In someembodiments, a description of the appointment, or a location associatedwith the appointment, or both, are included in the calendar data foreach appointment. Individual electronic calendars may also be maintainedby calendar database system 130 for physical assets such as conferenceMOMS.

In exemplary embodiments, the calendaring services provided by calendardatabase system 130 can be accessed using electronic calendaringapplications residing on clients 120. Calendar database server 140 canaccept individual electronic calendar appointments for each individualelectronic calendar, and each of the accepted appointments may include astart date/time and either a stop time or a duration of the appointmenton a particular day or days. Each electronic calendar appointment mayalso include information describing the location of the scheduledappointment. Calendar database system 130 can be configured such thatcalendar database server 140 is a shared server that provides usercalendar data 150 as a common database for storing and accessinginformation related to a calendar of events for a group of users ofclients 120. Calendar database system 130 can also be configured toallow a user to operate an electronic calendaring application toorganize a meeting by specifying a time, a date, a duration, and a listof mandatory attendees and/or optional attendees for the meeting fromthe users user maintaining an individual electronic calendars on system100, and send electronic messages notifying each attendee of the meetingand allowing optional attendees to accept or decline participation inthe meeting. Calendar database system 130 can further be configured toadd an appointment that corresponds to the meeting to the individualelectronic calendar of each user specified as a mandatory attendee andeach user specified as an optional attendee that accepts participationin the meeting.

For purposes of illustration, calendar database server 140 is depictedas being separate from clients 120; but in other exemplary embodiments,calendar database server 140 can be distributed over or reside in partor in whole on one or more of clients 120. Furthermore, for purposes ofillustration, one calendar server 140 is connected to one storage devicewith user calendar data 150, but in other embodiments, the user calendardata may be distributed over several data storage devices connecteddirectly to one or more calendar database servers like calendar databaseserver 140, or connected indirectly to one or more servers throughnetwork 110. Any suitable database system type may be used as calendardatabase system 130. In exemplary embodiments, system 100 can includemore or fewer calendar database systems like system 130.

Electronic event organizing system 100 also includes an event databasesystem 160, which includes an event server 170 and event data 180 on oneor more storage devices. Event server 170 controls the storage andretrieval of event data 180. For purposes of illustration, server 170 isshown separate from clients 120; but in some embodiments, server 170resides in part or in whole on one or more of clients 120. Furthermore,for purposes of illustration, one server 170 is connected to one storagedevice with event data 180, but in other embodiments, the event data maybe distributed over several data storage devices connected directly toone or more servers like server 170, or connected indirectly to one ormore servers through network 110. Any suitable data system type may beused as event data system 160. In some embodiments, one or more eventdata servers like server 170 can be embedded in calendar database server140. In some embodiments, some or all of event data 180 is included onthe same storage device or within the same storage records as usercalendar data 160.

System 100 also includes an event management server 190. Eventmanagement server 190 provides services for organizing the schedule foran event and distributing the schedule to the attendees of the event.Event management server 190 can thereby allow individual users, who maybe persons operating one of clients 120, to schedule events among theusers maintaining individual electronic calendars on system 100. Inexemplary embodiments, the event scheduling services provided by eventmanagement system 130 can be accessed using functionality implementedwithin electronic calendaring applications residing on clients 120. Theelectronic calendaring applications can comprise, for example,applications provided for a workgroup and server oriented calendaringsystem, client-based calendaring applications such as Microsoft Outlook,and/or web services-based calendaring applications such as MSN Alerts orYahoo! Alerts. The functionality for accessing the event schedulingservices may be implemented, for example, as an aspect of a softwarepackage for the electronic calendaring applications, or as a softwaremodule or component implemented for incorporation with the electroniccalendaring applications as, for example, one or more libraries offunctions, one or more plug-in or extension modules, one or more dynamiclink-libraries, etc.

In exemplary embodiments, event management server 190 can be part ofcalendar database server 140. For purposes of illustration, eventmanagement server 190 is depicted as being separate from clients 120 andservers 150, 180; but in some embodiments, event management server 190can reside in part or in whole on one or more of clients 120 or on aclient with other depicted systems 130, 160 or as part of servers 150,180. In some exemplary embodiments, event management server 190 may bedistributed over several clients connected to network 110.

Referring now to FIG. 2, a block diagram of an exemplary embodiment ofan event management mechanism 200 in accordance with the presentinvention is illustrated. Event management mechanism 200 can beimplemented, for example, within event management server 190 describedabove with reference to the exemplary embodiment illustrated in FIG. 1,to allow a user to organize and schedule an event, such as a conferencewith multiple presentations or an office visit, that involves a numberof different participants that will be attending a number of sessions ormeetings related to different sub-topics, in which attendance is eitheroptional or mandatory for certain of the participants at certain of themeetings, and in which the multiple meetings can each involve furthersub-meetings for which attendance may be either optional or mandatoryfor the participants of the meeting. In exemplary embodiments in whichevent management mechanism 200 is implemented within event managementserver 190 of system 100, the participants of the event can include, forexample, users of clients 120 having individual electronic calendarsmaintained by in user calendar data 150.

In the present exemplary embodiment, event management mechanism 200includes an attribute input accepting module 210, a schedule planningmodule 220, a schedule notification module 230, and a schedule updatemodule 240. As used herein, the terms “module” and “program module” bothinclude routines, programs, objects, components, data structures, andinstructions, or instructions sets, and so forth that perform particulartasks or implement particular abstract data types. As can beappreciated, the modules can be implemented as software, hardware,firmware and/or other suitable components that provide the describedfunctionality, which may be loaded into memory of a machine embodyingexemplary embodiments of a version comparison mechanism in accordancewith the present invention. Aspects of the modules may be written in avariety of programming languages, such as C, C++, Java, etc. As usedherein, the term “data store” refers to any suitable memory device thatmay be used for storing data, including manual files, machine-readablefiles, and databases. The functionality provided by the modules and datastores described with reference to exemplary embodiments presentedherein can be combined and/or further partitioned.

Generally, attribute input acceptor 210 is implemented to receive inputdata providing information needed for scheduling of an event thatincludes an agenda of meetings for an event, the details of each of themeetings (for example, a location for each meeting), and informationregarding the invitees or attendees for the event (for example, theparticular meetings each of the invitees will be invited to attend, andwhether their attendance for each meeting to which they will be invitedis optional or mandatory); schedule planner 220 is implemented to plan aschedule for the event based on the event information received byattribute input acceptor 210 and store the planned event schedule inevent schedule 250; schedule notification module 230 is implemented toaccess event schedule 250 and produce an output that can be rendered fordisplaying the event schedule planned by schedule planner 220, togenerate and send electronic messages to each of the invitees providingthe planned schedule for the entire event and a notification of each ofthe meetings to which the invitee has been invited, as well as toproduce an interface accessible by the attendees through, for example,an electronic calendaring application, for notifying attendees ofscheduled meetings of which they are to be informed, notifying attendeesof scheduled meetings for which their participation is mandatory,notifying the optional attendees of scheduled meetings and providingthese attendees with the option of accepting or declining theinvitation, notifying the attendees of relevant updates to the eventschedule, and updating their respective electronic calendarsaccordingly; and schedule updater 240 is implemented to acceptmodifications to the information provided to attribute input acceptor210 for scheduling the event, which can thereby permit schedule planner220 to re-plan the schedule for the conference accordingly and schedulenotification module 230 to generate new outputs corresponding to there-planned schedule.

With more particularity, attribute input acceptor 210 is implemented toallow the event chair to define an event that comprises multiplesub-meetings by specifying values for a set of attributes for the eventand for each sub-meeting, and then submit the event as defined in thisfashion to event management mechanism 200 for scheduling in accordancewith the specified set of parameters. Each of the values for theattributes of each meeting object instance for the event can either besubmitted by the event chair through a user interface implemented withinevent management mechanism 200 or imported from information recorded inan external data store such as, for example, data from individualelectronic calendars maintained for invitees to the event and/or flatfiles of data containing event overview data and a list of attendees.The event chair can also specify, for each value, from where theinformation for that value is to be obtained.

In exemplary embodiments in which event management mechanism 200 isimplemented within event management server 190 of system 100, eventmanagement mechanism 200 can be configured to maintain the data for theevent as defined through input values received by attribute inputacceptor 210 in event data 180 of event database system 160, and thevarious modules included within the event management mechanism can beconfigured to store, retrieve, and operate on data for the event byaccessing the event data through event 170. Furthermore, in theseembodiments, the event management mechanism can be configured to providean interface mechanism that can be utilized the chair user for inputtingparameters for an event and sub-meetings for the event to be scheduledand directing the event management mechanism to plan a schedule for theevent accordingly. This interface mechanism can be, for example,incorporated within and provided through a user interface implemented byelectronic calendaring applications being operated by users of clients120. For example, the interface mechanism can be accessible for definingan event when a user selects an “Add Event” button provided through theuser interface of the calendaring application, and while being accessedfor event, the interface mechanism can be further accessible fordefining a sub-meeting by selecting an “Add Sub-meeting” button. Inexemplary embodiments, the interface mechanism can be furtherimplemented to provide interface elements that can be accessed to allowa user to modify, delete, view, or otherwise operate upon the definedevent and sub-meetings, as well as the attribute values submittedtherefore.

For each event and for each sub-meeting, attribute input acceptor 210instantiates an instance of a meeting object that includes an attributefield for holding a value for each attribute that can be specified for ameeting. In particular, in the present exemplary embodiment, eachmeeting object instance includes attribute fields for maintaining valuesfor a meeting ID, a meeting type, a meeting chair (the chair for anevent is the event chair that defines the event and the sub-meetings tobe scheduled for the event), a meeting location, a list of invitees, ameeting start time and date, and a meeting duration. The value for themeeting type attribute field can be specified as an event, a group, or asession. A meeting object instance having an event meeting type value isalso defined with a specified meeting duration within which allsub-meetings for the event are to be scheduled. A meeting objectinstance having a group meeting type value corresponds to a subset ofthe set of all sub-meetings for the event and is defined with aspecified meeting duration within which all of the sub-meetings in thesubset of sub-meetings defined for the group are to be scheduled. Ameeting object instance having a session meeting type value correspondsto a particular sub-meeting of the event to be scheduled by eventmanagement mechanism 200. Meeting object instances having event or groupmeeting type values do not correspond to sessions to be scheduled byevent management mechanism 200. Rather, each meeting object instancehaving an event or a group meeting type value includes attribute valuesspecified to provide parameters for scheduling the sub-meetings thathave meeting object instances encompassed by that event or a groupmeeting object instance.

Thus, it can be seen that, in the present exemplary embodiment, themeeting object instances can be represented using a hierarchicalstructure in which sub-meetings that are defined by meeting objectinstances encompassed by an event or a group meeting object instancehave a parent-child relationship with the encompassing event or a groupmeeting object instance. Sub-meetings that are defined by meeting objectinstances encompassed by an event or a group meeting object instance caninherit attribute values from the encompassing event or a group meetingobject instance. The meeting chair for each sub-meeting that is defineda meeting object instance encompassed by an event or a group meetingobject instance can be defined by the specified meeting chair for theencompassing event or a group meeting object instance.

Each meeting object instance for a sub-meeting having a parent-childrelationship with an event meeting object instance, as specified by theevent chair for the event, can be referred to as a “first-levelsub-meeting”, and once defined by the event chair, the meeting chair foreach first-level sub-meeting can define further define meeting objectinstances for sub-meetings having a parent-child relationship with thefirst-level sub-meeting, referred to as “second-level sub-meetings”, andassign a meeting chair for each second-level sub-meeting. The meetingchair for each second-level sub-meeting can further define “third-levelsub-meetings” (in which the second-level sub-meeting and eachthird-level sub-meeting have a parent-child relationship) and assign ameeting chair thereto, and so on. For example, a first chair can provideparameters for a parent meeting object instance having an event meetingtype and a child meeting object instance having a group meeting type. Ifthe first chair assigns a second chair for the meeting object instancehaving a group meeting type, the second chair can then provideparameters defining one or more meeting object instances forsub-meetings encompassed by the parent meeting object instance having agroup meeting type.

Meeting object instances having non-event meeting types (that is,session or group meeting types, which correspond to sub-meetings) can befurther defined to store values for additional attributes that include aspeaker or presenter name, a list of invitees for whom attendance ismandatory, a list of invitees for whom attendance is optional, a list ofpersons to be informed about the meeting, a reference to a parentmeeting object instance (indicating the event or group meeting objectinstance for the meeting object instance having the referenceattribute), a Boolean value indicating whether the start time for thesub-meeting is fixed or variable, and a set of references to predecessormeeting object instances indicating which, if any, of the othersub-meetings must be scheduled to take place prior to the sub-meetingcorresponding to that meeting object instance. A meeting object instancehaving a group meeting type may or may not include a specified value forthe speaker.

As mentioned above, a child meeting object instance for a sub-meetingcan inherit attribute values from its parent meeting object instance.The specific attributes that are inherited by a child meeting objectinstance can be specified by the meeting chair for the parent meetingobject instance. Child meeting object instances for sub-meetings havinga variable start time can be indicated as such by specifying that themeeting start time attribute is to be inherited from the parent meetingobject instance. The meeting chair for a parent meeting object instancecan also specify whether each attribute for each child meeting objectinstance is modifiable or locked. An attribute of a meeting objectinstance that is defined as being modifiable can then be modified by themeeting chair assigned for that meeting object instance.

Referring now to FIG. 3 a, an example set of meeting object instances300 (which can be instantiated, for example, by attribute input acceptor210 of the exemplary embodiment illustrated in FIG. 2) for an event anda set of sub-meetings for the event is illustrated in a hierarchicaltree representation. The event is an organized visit to a corporateoffice by Customer X. Meeting object instances 300 include an instancefor the event Customer X Visit 310 defined according parameters providedby event chair Carol. As indicated by the parent reference attributes ofmeeting object instances 300, Customer X Visit 310 is a parent meetingobject instance for the child meeting object instances for sub-meetingsWelcome 320, Innovation Land 330, and Closing 340. Sub-meetings Welcome320 and Closing 340 are sub-meetings provided with meeting objectinstances having a session meeting type. Innovation Land 330 is asub-meeting provided with a meeting object instance having a groupmeeting type and Veran as an assigned chair. As indicated by the parentreference attributes of meeting object instances 300, Innovation Land330 is a parent meeting object instance for the child meeting objectinstances for sub-meetings Near Field Communication 350, Instant Gaming360, and Video on Demand 370. As indicated by the predecessor referenceattributes of meeting object instances 300, Welcome 320 should bescheduled to precede Innovation Land 330, Welcome 340 should bescheduled to precede the sub-meetings of the group encompassed byInnovation Land 330 group, Video on Demand 370 should be scheduled toprecede Instant Gaming 360, and all other sub-meetings of the eventencompassed by Customer X Visit 310 should be scheduled to precedeClosing 340. In FIG. 3 a, arrows having solid lines indicate theparent-child relationships between the meeting object instances, andarrows having dashed lines indicate the predecessor relationshipsbetween the meeting object instances.

Referring again to the exemplary embodiment illustrated in FIG. 2,attribute input acceptor 210 can be implemented to organize the meetingobject instances defined for an event and their respective attributes,and to provide the organized meeting object instances in a table format.For example, attribute input acceptor 210 can be configured to organizethe parameters provided for the example event Customer X Visit 310 intoa table 380, as depicted in FIG. 3 b. Table 380 represents theparameters provided for Customer X Visit 310 and each of meeting objectinstances 300 of the sub-meetings encompassed thereby. For example,because Customer X Visit 310 has an event meeting type, table 380 doesnot include defined parameters for mandatory invitees, parent reference,predecessor reference, and a fixed time for Customer X Visit 310. Also,as represented in table 300, the sub-meetings defined in Welcome 320,Near Field Communication 350, and Video on Demand 370 are specified ashaving a fixed start time.

Schedule planner 220 is implemented to plan a schedule for the eventbased on the event information accepted and organized by attribute inputacceptor 210, as described, and to submit the planned schedule for theevent to schedule notifier 140. In exemplary embodiments, the scheduleplanner can be implemented to plan the schedule for the event accordingto an event scheduling process 400 provided by the flow chartsillustrated in FIGS. 4 a and 4 b. Referring initially to FIG. 4 a, inexemplary process 400, at block 410, schedule planner 220 receives theevent parameters provided to and organized by attribute input acceptor210 for the meeting object instances defining the event and itssub-meetings.

At block 420, schedule planner 220 generates a listing of all possibletime slots within which each sub-meeting corresponding to a meetingobject instance having a session meeting type may be scheduled. Thelisting can, for instance, be provided in a table format, as depicted bytable 390 a in FIG. 3 c for an example event. Table 390 a lists thesub-meetings to be scheduled for the example event by the meeting IDattribute value of their respective meeting object instances in a headercolumn and the available time slots sequentially in a header row. Thetime length of each time slot in the listing generated at block 420 cancorrespond to the least common denominator of the time length values forall the duration attributes provided for the meeting object instances ofthe event. As a result, the duration attribute values for each meetingobject instance can be represented by an integer value that correspondsto the number of time slots encompassed by the time length of theduration attribute value for the meeting object instance. The possibletime slots listed for each sub-meeting in the listing generated at block420 are determined according to relationships between the meeting objectinstance attribute values for location and mandatory invitees. Theseattributes are used to limit the possible time slots by listing only aspossible those time slots that do not involve an unresolvable conflict,as two sub-meetings cannot be scheduled for the same time at the samelocation, and a mandatory invitee for a sub-meeting cannot attend asub-meeting as required if the invitee is unavailable during thescheduled time slot for the sub-meeting or required to attend anothersub-meeting as a mandatory invitee at the same scheduled time slot. Aswill be described, schedule planner 220 uses the listing of possibletime slots generated at block 420 to plan an optimized schedule for theevent.

At block 430, schedule planner 220 modifies the listing generated atblock 420 to limit the possible time slots within which each sub-meetingcorresponding to a session or group meeting object instance may bescheduled according to the duration attributes in the parametersprovided to attribute input acceptor 210. Because some meeting objectinstances can be defined with a duration that extends over multiple timeslots, schedule planner 220 can be implemented to, at block 430,suppress the possible time slots in the listing generated at block 420for such meeting object instances to only those included within sets ofmultiple, contiguous time slots that together are sufficient to coverthe entire time length of the duration specified for the time slots(that is, sets of multiple, contiguous time slots having an aggregatetime length that is greater than or equal to the duration value of themeeting object instance). It is not necessary for schedule planner 220to suppress the possible time slots for meeting object instances thathave a specified meeting start time value and a duration thatcorresponds to multiple time slots, as the listing generated at block420 will have only yielded one possible set of contiguous time slotslisted for the sub-meeting. At block 440, schedule planner processes thelisting to generate a count of possible sets of time slots for eachsub-meeting and a count of the possible sub-meetings for which each timeslot can be allocated.

The modified listing resulting from the operations performed at block430 can, for example, be generated in table format, as depicted by table390 b in FIG. 3 d for the example event represented by table 390 a inFIG. 3 c. Table 390 b lists the sub-meetings to be scheduled for theexample visit by their meeting ID attribute value in a header column andthe available time slots sequentially in a header row. As shown in theinformation provided by table 390 b, the table format for the listinggenerated at block 430 can also include the count of possible sets oftime slots for scheduling each the sub-meeting and the count of thepossible sub-meetings for which each time slot can be allocated asgenerated at block 440.

In the present exemplary embodiment, at block 450, for each session typemeeting object instance having a start time attribute value that isspecified as being fixed, schedule planner 220 performs the sessionscheduling process provided in blocks 452-468 of FIG. 4 b and describedin detail below for scheduling the sub-meeting and then updating thelisting of all possible time slots within which each sub-meeting havinga session type meeting object instance may be scheduled according torelationships between the attributes of the meeting object instances forstart times, durations, and references to predecessor meetings. Afterscheduling each session type meeting object instance having a start timeattribute value that is specified as being fixed, at block 470, scheduleplanner 220 resolves the remaining meeting schedule by performing thesession scheduling process provided in blocks 452-468 in the order fromsub-meetings having the lowest count of possible sets of time slotswithin which the sub-meeting can be scheduled to sub-meetings having thehighest count of possible sets of time slot(s) within which thesub-meeting can be scheduled.

More specifically, schedule planner 220 first performs the sessionscheduling process provided in blocks 452-468 for each sub-meetinghaving only one possible set of time slots covering the duration valueof the meeting object instance corresponding to the sub-meeting in thelisting of all possible time slots within which each sub-meeting may bescheduled. As will be described, after allocating a set of time slotsfor a particular sub-meeting during the session scheduling process,schedule planner 220 updates the count of possible sets of time slotsfor each unscheduled sub-meeting and the count of the possiblesub-meetings for which each time slot can be allocated. Dynamicallyupdating the counts after scheduling each sub-meeting enables scheduleplanner 220 to perform the session scheduling process provided in blocks452-468 for each sub-meeting having only one possible set of time slotsuntil there are no sub-meetings having only one possible set of timeslots remaining. If there are any remaining sub-meetings to be scheduledafter no sub-meetings having only one possible set of time slots remainto be scheduled, schedule planner 220 then performs the sessionscheduling process provided in blocks 452-468 for each sub-meetinghaving only two possible set of time slots until there are nosub-meetings having only two possible sets of time slots remaining to bescheduled. Schedule planner 220 will continue in fashion by sequentiallyincrementing the specified number of possible sets of time slots andperforming the session scheduling process provided in blocks 452-468 foreach sub-meeting having the specified number of possible set of timeslots until there are no sub-meetings remaining to be scheduled. Wherethere are multiple sub-meetings having the specified number of possibleset of time slots, the order in which these sub-meetings are scheduledby schedule planner 120 can be determined according to, for example, theorder of sub-meetings having the earliest occurring possible sets oftime slots, according to priority values submitted for the sub-meetings(the priority values can, for example, be submitted to schedule planner220), or predecessor values. At this point, schedule planner 220 willhave generated a schedule for the entire event.

The session scheduling process performed by schedule planner 220 in thepresent exemplary embodiment, as provided in blocks 452-468, will now bedescribed in greater detail. The process illustrated in blocks 452-468is performed for each sub-meeting to be scheduled in the order describedabove. For the present sub-meeting being scheduled, at decision block452, schedule planner 220 determines whether any of the possible sets oftime slots within which the sub-meeting may be scheduled is available.For instance, if there is only one possible set of time slots withinwhich the sub-meeting may be scheduled listed (for example, for asub-meeting corresponding to a meeting object instance having a fixedstart time), schedule planner 220 determines if the time slot(s)corresponding to the start time for the possible set of time slots forthe sub-meeting and the duration specified for the sub-meeting is or areavailable. That is, schedule planner 220 determines whether any of thepossible set of time slots have been allocated for another sub-meetinghaving a session type meeting object instance that has already beenscheduled, whether there are any predecessor relationships specified inthe meeting object instances that would prevent the sub-meeting frombeing scheduled in the possible set of time slots, or whether, if thesub-meeting being scheduled corresponds to a meeting object instance forwhich a fixed start time has been specified, any of the time slotscorresponding to the fixed start time and the duration attribute valuesof the meeting object instance were not included in the listing ofpossible time slots generated at block 420 as a result of conflictsarising due to the relationships between the meeting object instanceattribute values for location and mandatory invitees. On the other hand,if there is more than one possible set of time slots within which thesub-meeting may be scheduled listed, schedule planner 220 determines,for each possible set of time slots sequentially (for instance, in orderfrom earliest to latest), if the time slot(s) corresponding to the starttime for the possible set of time slots for the sub-meeting and theduration specified for the sub-meeting is or are available as describedabove until one of the possible sets of time slots is determined to beavailable or each of the possible sets of time slots is determined tonot be available.

If schedule planner 220 determines, at decision block 452, that, foreach of the each of the possible sets of time slots for the sub-meeting,there is at least one time slot in the set that is not available (forany of the reasons specified above), the process proceeds to block 454,at which the schedule planner generates a request for the event chair(or for the meeting chair for a group message object instance thatencompasses the sub-meeting) to submit new attribute values for themessage object instance corresponding to the sub-meeting throughattribute input acceptor 210 that will allow the sub-meeting to bescheduled in an available time slot. In exemplary embodiments in whichevent management mechanism 200 is implemented within event managementserver 190 of system 100 (as described with reference to FIG. 1 above),this request can be provided to the event chair through, for example,the user interface implemented within the electronic calendaringapplication operating on one of clients 120.

After either schedule planner 220 has determined at decision block 452that there is a possible set of time slots for the sub-meeting that isavailable or new attribute values for the message object instancecorresponding to the sub-meeting have been submitted at block 454, atblock 456, schedule planner 220 schedules the sub-meeting by allocatingthe set of time slots corresponding to either the possible set of timeslots identified as being available at decision block 452 or the set oftime slots corresponding to the new attribute values submitted for themessage object instance corresponding to the sub-meeting at block 454 inevent schedule 250. Then, at block 458, schedule planner 220 removes anytime slots from the listing of possible time slots within which each ofthe other sub-meetings may be scheduled that correspond to any timeslots allocated for the scheduled sub-meeting at block 456 or that wouldconflict with any predecessor relationships specified in the meetingobject instances. At block 460, schedule planner 220 removes any othertime slots not allocated for the scheduled sub-meeting from the listingof possible time slots for which the scheduled sub-meeting could havebeen scheduled.

As described above, schedule planner 220 is implemented to repeat thesession scheduling process encompassed by block 450 for each sessiontype meeting object instance corresponding to a sub-meeting until thereare no sub-meetings remaining to be scheduled. To provide for this, atdecision block 462, schedule planner 220 determines whether there areany sub-meetings remaining to be scheduled. If there are no sub-meetingsremaining to be scheduled, the event schedule is complete, and exemplaryprocess 400 terminates. If there are sub-meetings remaining to bescheduled, at decision block 464, schedule planner 220 updates, for eachsub-meeting remaining to be scheduled, the count of possible sets oftime slot(s) for scheduling the sub-meeting and the count of thepossible sub-meetings for which each time slot can be allocated. Then,at decision block 466, schedule planner 220 determines if any of thesub-meetings remaining to be schedule have a count of possible timeslots that is equal to specified number of possible sets of time slots.If any of the sub-meetings have a count of possible time slots that isequal to specified number of possible sets of time slots, scheduleplanner 220 repeats the session scheduling process for the nextsub-meeting to be scheduled. If none of the sub-meetings have a count ofpossible time slots that is equal to specified number of possible setsof time slots, schedule planner 220, at block 468, increments thespecified number of possible sets of time slots until at least one ofthe sub-meetings remaining to be scheduled has a count of possible timeslots that is equal to specified number of possible sets of time slots.Schedule planner 220 then repeats the session scheduling process for thenext sub-meeting to be scheduled.

Referring again to FIG. 2, once schedule planner 220 has allocated timeslots for all of the sub-meetings of an event being scheduled in eventschedule 250, schedule notification module 230 is configured to accessevent schedule 250 to produce an output display that can be rendered forviewing the schedule planned by schedule planner 220, and to generateand send event schedule messages to each of the attendees containing theplanned schedule information for each of the sub-meetings to which theattendee has been invited. The event schedule messages can be generatedindividually for each of the attendees. The message generated for eachattendee can include the output display allowing the attendee to viewthe entire event schedule, as well as a notification of each sub-meetingfor which the attendee's participation is mandatory or optional, as wellas a notification of each sub-meeting for which the attendee is includedin the list of persons who should be informed about the meeting in themeeting object instance indicates that corresponding to the sub-meeting.

In exemplary embodiments in which event management mechanism 200 isimplemented within event management server 190 of system 100, the eventschedule messages for each attendee generated by schedule notificationmodule 230 can be further implemented to, upon being received by amessaging application incorporated within the attendee's electroniccalendaring application being operated on one of clients 120, direct theelectronic calendaring application to place each of the sub-meetings forwhich the attendee's participation is specified as mandatory on theattendee's electronic calendar according to the date, time, and durationattribute values specified for the sub-meeting, as well as to provide anoption for the attendee to accept or decline each invitation to asub-meeting for the attendee's participation is specified as optional.The event schedule message can also be implemented to provide an optionfor the attendee to accept or decline participation in each sub-meetingfor which the attendee has been specified as a person who should beinformed of the sub-meeting. This option can provided, for example,through a user interface element provided through the user interfaceimplemented within the attendee's electronic calendaring application.When an attendee selects the option to accept participation in asub-meeting, the attendee's electronic calendaring application can bedirected to place the sub-meetings on the attendee's electronic calendaraccording to the date, time, and duration attribute values specified forthe sub-meeting. Additionally, when an attendee selects the option toaccept or the option to decline participation in a sub-meeting, theattendee's electronic calendaring application can be directed to send areply message to the chair for the sub-meeting notifying the chair ofsuch.

In the present exemplary embodiment, as discussed above, scheduleupdater 240 is implemented to accept modifications to the attributes ofthe meeting object instances corresponding to the event and thesub-meetings for the event as provided to attribute input acceptor 210,and direct schedule planner 220 to re-plan the schedule for theconference accordingly in event schedule 250. In exemplary embodimentsin which event management mechanism 200 is implemented within eventmanagement server 190 of system 100, the functionality for modifying anevent or a sub-meeting in the manner can be provided via an interfaceelement incorporated within the user interface implemented by electroniccalendaring applications being operated by the respective chair for theevent or sub-meeting on one of clients 120. Schedule planner 220 can beimplemented to plan the subsequent schedule based on the modified set ofmeeting object instances in a similar manner as described above, andschedule notification module 230 can be implemented to access eventschedule 250 to generate new outputs corresponding to the re-plannedschedule. The new outputs can include a revised output display that canbe rendered for viewing the schedule planned by schedule planner 220,and to generate and send event schedule messages for each sub-meetingthat has been rescheduled in the subsequent schedule to each of theattendees specified as having mandatory or optional participation in therescheduled sub-meeting, each of the attendees specified as havingmandatory participation for the sub-meeting in the previous schedule,each of the attendees who had selected the option to acceptparticipation for the sub-meeting in the previous schedule, and eachattendee that is specified as a person who should informed of thesub-meeting. The event schedule messages can also be implemented todirect the affected attendees' electronic calendaring applications toupdate the attendees' electronic calendars accordingly.

In the preceding description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the described exemplary embodiments. Nevertheless, oneskilled in the art will appreciate that many other embodiments may bepracticed without these specific details and structural, logical, andelectrical changes may be made.

Some portions of the exemplary embodiments described above are presentedin terms of algorithms and symbolic representations of operations ondata bits within a processor-based system. The operations are thoserequiring physical manipulations of physical quantities. Thesequantities may take the form of electrical, magnetic, optical, or otherphysical signals capable of being stored, transferred, combined,compared, and otherwise manipulated, and are referred to, principallyfor reasons of common usage, as bits, values, elements, symbols,characters, terms, numbers, or the like. Nevertheless, it should benoted that all of these and similar terms are to be associated with theappropriate physical quantities and are merely convenient labels appliedto these quantities. Unless specifically stated otherwise as apparentfrom the description, terms such as “executing” or “processing” or“computing” or “calculating” or “determining” or the like, may refer tothe action and processes of a processor-based system, or similarelectronic computing device, that manipulates and transforms datarepresented as physical quantities within the processor-based system'sstorage into other data similarly represented or other such informationstorage, transmission or display devices.

Exemplary embodiments of the present invention can be realized inhardware, software, or a combination of hardware and software. Exemplaryembodiments can be implemented using one or more program modules anddata storage units. Exemplary embodiments can be realized in acentralized fashion in one computer system or in a distributed fashionwhere different elements are spread across several interconnectedcomputer systems. Any kind of computer system—or other apparatus adaptedfor carrying out the methods described herein—is suited. A typicalcombination of hardware and software could be a general-purpose computersystem with a computer program that, when being loaded and executed,controls the computer system such that it carries out the methodsdescribed herein.

Exemplary embodiments of the present invention can also be embedded in acomputer program product, which comprises all the features enabling theimplementation of the methods described herein, and which—when loaded ina computer system—is able to carry out these methods. Computer programmeans or computer program as used in the present invention indicates anyexpression, in any language, code or notation, of a set of instructionsintended to cause a system having an information processing capabilityto perform a particular function either directly or after either or bothof the following: (a) conversion to another language, code or, notation;and (b) reproduction in a different material form.

A computer system in which exemplary embodiments can be implemented mayinclude, inter alia, one or more computers and at least a computerprogram product on a computer readable medium, allowing a computersystem, to read data, instructions, messages or message packets, andother computer readable information from the computer readable medium.The computer readable medium may include non-volatile memory, such asROM, Flash memory, Disk drive memory, CD-ROM, and other permanentstorage. Additionally, a computer readable medium may include, forexample, volatile storage such as RAM, buffers, cache memory, andnetwork circuits. Furthermore, the computer readable medium may comprisecomputer readable information in a transitory state medium such as anetwork link and/or a network interface including a wired network or awireless network that allow a computer system to read such computerreadable information.

FIG. 5 is a block diagram of an exemplary computer system 500 that canbe used for implementing exemplary embodiments of the present invention.Computer system 500 includes one or more processors, such as processor504. Processor 504 is connected to a communication infrastructure 502(for example, a communications bus, cross-over bar, or network). Varioussoftware embodiments are described in terms of this exemplary computersystem. After reading this description, it will become apparent to aperson of ordinary skill in the relevant art(s) how to implement theinvention using other computer systems and/or computer architectures.

Exemplary computer system 500 can include a display interface 508 thatforwards graphics, text, and other data from the communicationinfrastructure 502 (or from a frame buffer not shown) for display on adisplay unit 510. Computer system 500 also includes a main memory 506,which can be random access memory (RAM), and may also include asecondary memory 512. Secondary memory 512 may include, for example, ahard disk drive 514 and/or a removable storage drive 516, representing afloppy disk drive, a magnetic tape drive, an optical disk drive, etc.Removable storage drive 516 reads from and/or writes to a removablestorage unit 518 in a manner well known to those having ordinary skillin the art. Removable storage unit 518, represents, for example, afloppy disk, magnetic tape, optical disk, etc. which is read by andwritten to by removable storage drive 516. As will be appreciated,removable storage unit 518 includes a computer usable storage mediumhaving stored therein computer software and/or data.

In exemplary embodiments, secondary memory 512 may include other similarmeans for allowing computer programs or other instructions to be loadedinto the computer system. Such means may include, for example, aremovable storage unit 522 and an interface 520. Examples of such mayinclude a program cartridge and cartridge interface (such as that foundin video game devices), a removable memory chip (such as an EPROM, orPROM) and associated socket, and other removable storage units 522 andinterfaces 520 which allow software and data to be transferred from theremovable storage unit 522 to computer system 500.

Computer system 500 may also include a communications interface 524.Communications interface 524 allows software and data to be transferredbetween the computer system and external devices. Examples ofcommunications interface 524 may include a modem, a network interface(such as an Ethernet card), a communications port, a PCMCIA slot andcard, etc. Software and data transferred via communications interface524 are in the form of signals which may be, for example, electronic,electromagnetic, optical, or other signals capable of being received bycommunications interface 524. These signals are provided tocommunications interface 524 via a communications path (that is,channel) 526. Channel 526 carries signals and may be implemented usingwire or cable, fiber optics, a phone line, a cellular phone link, an RFlink, and/or other communications channels.

In this document, the terms “computer program medium,” “computer usablemedium,” and “computer readable medium” are used to generally refer tomedia such as main memory 506 and secondary memory 512, removablestorage drive 516, a hard disk installed in hard disk drive 514, andsignals. These computer program products are means for providingsoftware to the computer system. The computer readable medium allows thecomputer system to read data, instructions, messages or message packets,and other computer readable information from the computer readablemedium. The computer readable medium, for example, may includenon-volatile memory, such as Floppy, ROM, Flash memory, Disk drivememory, CD-ROM, and other permanent storage. It can be used, forexample, to transport information, such as data and computerinstructions, between computer systems. Furthermore, the computerreadable medium may comprise computer readable information in atransitory state medium such as a network link and/or a networkinterface including a wired network or a wireless network that allow acomputer to read such computer readable information.

Computer programs (also called computer control logic) are stored inmain memory 506 and/or secondary memory 512. Computer programs may alsobe received via communications interface 524. Such computer programs,when executed, can enable the computer system to perform the features ofexemplary embodiments of the present invention as discussed herein. Inparticular, the computer programs, when executed, enable processor 504to perform the features of computer system 500. Accordingly, suchcomputer programs represent controllers of the computer system.

Although exemplary embodiments of the present invention have beendescribed in detail, the present description is not intended to beexhaustive or limiting of the invention to the described embodiments. Itshould be understood that various changes, substitutions and alterationscould be made thereto without departing from spirit and scope of theinventions as defined by the appended claims. Variations described forexemplary embodiments of the present invention can be realized in anycombination desirable for each particular application. Thus particularlimitations, and/or embodiment enhancements described herein, which mayhave particular advantages to a particular application, need not be usedfor all applications. Also, not all limitations need be implemented inmethods, systems, and/or apparatuses including one or more conceptsdescribed with relation to exemplary embodiments of the presentinvention.

The exemplary embodiments presented herein were chosen and described tobest explain the principles of the present invention and the practicalapplication, and to enable others of ordinary skill in the art tounderstand the invention. It will be understood that those skilled inthe art, both now and in the future, may make various modifications tothe exemplary embodiments described herein without departing from thespirit and the scope of the present invention as set forth in thefollowing claims. These following claims should be construed to maintainthe proper protection for the present invention.

1. A method of scheduling events having multiple meetings and multipleattendees, the method comprising: receiving, using a server of acomputer system, a set of event data including a plurality of sessionseach comprising a plurality of sub-meetings, an event duration thatencompasses a plurality of time slots, a respective duration for eachsub-meeting, a respective start time for the event and each of theplurality of sub-meetings, and a set of information describing aplurality of event attendees that includes a respective list of one ormore mandatory attendees for each sub-meeting; generating a first listof each possible set of time slots from the plurality of time slots foreach session within which the session can be scheduled based upon thespecified lists of one or more mandatory attendees and the respectivestart times for the sub-meetings; generating a second list by removingeach possible set of time slots from the first list for each sessionthat is less than the duration specified for the session; individuallyperforming a scheduling process for each session that comprisesallocating a respective set of time slots for the session in an eventschedule, removing each possible set of time slots for the session thatis not equivalent to the set of time slots allocated for the sessionfrom the second list, and removing each possible set of time slots foreach other session that includes at least one time slot allocated forthe session in the event schedule from the second list; and sending arespective electronic message presenting the event schedule to eachevent attendee of the plurality of event attendees.
 2. The method ofclaim 1, wherein the set of event data further specifies an indicationof whether the respective start time specified for each of the pluralityof sub-meetings is fixed and a respective predecessor reference for eachof the plurality of sub-meetings to a respective predecessor sub-meetingof the set of sub-meetings that must be scheduled to take place beforethe sub-meeting, wherein generating the first list is further based uponthe respective indication of whether the respective start time specifiedfor each of the plurality of sub-meetings is fixed such that the firstlist will include exactly one possible set of time slots for eachsession for which the respective start time is specified as being fixed,and wherein generating the second list further includes removing eachpossible set of time slots from the first list for each sessionspecified with a predecessor reference that cannot be scheduled aftereach possible set of time slots for the respective predecessorsub-meeting.
 3. The method of claim 2, wherein the scheduling process isfirst performed individually for each session specified with respectivestart time that is specified as being fixed, wherein the schedulingprocess is then performed individually for each session in order fromsessions having the fewest number of remaining possible sets of timeslots in the second list to sessions having the highest number, andwherein the scheduling process further comprises generating a requestfor the respective set of time slots to be allocated for the session ifthe session has zero remaining possible sets of time slots in the secondlist, receiving the respective set of time slots to be allocated for thesession if there are no remaining possible sets of time slots for thesession in the second list, and selecting one of the remaining possiblesets of time slots for the session in the second list as the respectiveset of time slots to be allocated for the session if there is at leastone remaining possible set of time slots for the session in the secondlist.
 4. The method of claim 1, wherein the set of sub-meetings furtherincludes one or more group sessions for the event, wherein set of eventdata specifies a hierarchical relationship for the event and the set ofsub-meetings with the event at a highest level of the hierarchicalrelationship, wherein each sub-meeting has a parent selected from theevent and the sub-meetings of the set of sub-meetings in thehierarchical relationship, wherein each sub-meeting can inherit eventdata from the set of event data specified for the parent of thesub-meeting, wherein each group session is the parent of at least one ofthe one or more sessions for the event, and wherein generating thesecond list further includes removing each possible set of time slotsfrom the first list for each session having one of the one or more groupsessions as the parent of the session that is not within the respectiveduration specified for the group session.
 5. The method of claim 2,wherein individually performing a scheduling process for each session isperformed within an event organizing system that includes a networkconnecting a plurality of client computers, a calendar database systemmaintaining a respective set of calendar data for each attendee of theplurality of attendees for the event, an event database system, and anevent management server, wherein each of the plurality of clientcomputers is configured with a calendaring application operable by eachattendee to access and operate on the respective set of calendar datafor the attendee, and wherein the event management server is configuredto receive the set of event data for the event, store the set of eventdata in the event database system, and operate on the set of event datato generate the first list, generate the second, and individuallyschedule each session in the event schedule.
 6. The method of claim 5,wherein the set of information describing a plurality of event attendeesfurther includes a respective list of one or more optional attendees foreach sub-meeting, wherein the respective electronic message sent to eachevent attendee in the respective list of mandatory attendees for eachsession is configured to direct the calendaring application to accessthe calendar database system to schedule the allocated set of time slotsfor the session in the respective set calendar data for the attendee,wherein the respective electronic message sent to each event attendee inthe respective list of optional attendees for each session is configuredto direct the calendaring application to present the attendee with anoption to accept or decline participation in the session, and whereinthe respective electronic message sent to each event attendee in therespective list of optional attendees for each session is configured todirect the calendaring application to access the calendar databasesystem to schedule the allocated set of time slots for the session inthe respective set calendar data for the attendee if the attendeeaccepts participation in the session.